Which flag indicates that a vessel is disabled and requires communication?

The Foxtrot flag is recognized internationally as the signal for a vessel that is disabled and in need of assistance. In maritime communication, the display of the Foxtrot flag indicates to other vessels that immediate help is required due to the inability of the vessel to navigate or operate normally. The use of this flag is crucial for ensuring safety at sea, as it alerts surrounding vessels to the situation and prompts them to maintain a safe distance or offer assistance.

The other flags listed—Hotel, Kilo, and November—communicate different messages. The Hotel flag indicates that a vessel is taking on fuel; the Kilo flag signifies a request for a pilot; and the November flag is used to signal a vessel's intention to communicate. Each flag has distinct meanings in maritime signal communication, they do not convey the need for assistance due to a vessel being disabled as the Foxtrot flag does.